Friction brake mechanism



April 7, 1925; 1,532,629

c. L. c. MAGEE.

FRICTION BRAKE MECHANISM Filed 001:. 3, 1920 F KENT oHAUncnY L'. o. niaonn, or CHICAGO, rnntnors.

FRICTION BRAKE EIEECHANISD'I.

Application filed Gctober 2, 1920. Serial No. 14,286.

To all whom it may concern:

Be it known that l, CI-IAUNGEY L. C. Means, a citizen of the United States, and a resident of the city of Chicago, in the county of Cook, in the State of Illinois, have invented certain new and useful Improvement in Friction Brake Mechanism, of which the following is a specification.

This is an improvement on the construction shown and described in copending application No. 414,285 filed of even date therewith. In said application a certain supporting member has a compression strain imposed thereon when the mechanism is operated to contract the band on the drum. In some situations that is desirable or necessary under the circumstances, while in other cases it is necessary or desirable to have a pull or tensile strain imposed on said member.

The object of the improvement herein shown and described, therefore, is to provide a construction and an arrangement whereby the member which is attached to the brake band to support the operating mechanism has a pull or tensile strain imposed thereon when the mechanism is operated to contract the band or the drum of the brake, as will more fully appear.

To these and other useful ends the invention consists in matters hereinafter set forth and claimed, and shown in the accompanying drawings, in which:

Figure 1 is a side elevation of a friction brake embodying the principles of the invention',

Figure 2 is an enlarged detail sectional view.

As thus illustrated, this invention comprises a drum 1, of any suitable character, secured to the motor vehicle wheel (not shown) in the usual manner, or arranged in any desired way, depending upon the character of the machine or apparatus in connection with which the brake is used. The band 2 is of any suitable character and its ends are provided with brackets 3 and t formed as shown. The rod 5 extends through these brackets, having a sliding engagement with the bracket 3 and a pulling engagement with the bracket 4:, a nut 6 being screwed upon the threaded upper end portion of the rod to bear against the bracket 4 as shown. The lower end of the rod 5 is secured to the flexible ner explained.

and resilient strip or member 7 which is secured by rivets 8 to the band. A collar 9 slides on the rod 5 either loosely or rigidly with the bracket 3, and a lever 10 is pivoted and thereby fulcruined on the collar 9 and connected by the link 11 with the lower end of the rod 5 so that a toggle joint is provided. Preferably, a guide 12 is mounted on some stationary portion of the vehicle or other machine, or supported in any suitable manner, between the brackets 25 and i, for the rod 5 to slide in, and coil springs 13 and 14 are interposed between said guide and the brackets. A U-shaped bracket 15 is secured to the band at a point diametrically opposite the guide 12, to enhat the band thus supported can contract on the drum. The support 16 is obviously stationary, or rigid, and can be supported or mounted in any suitable or desired man ner.

In use the pivotal points 17, 18 and 19, forming the toggle, are brought into alinement, or more nearly so than shown, to exert a downward pull on the bracket 4: and an upward push on the bracket 3, thus contracting the band on the drum. A pull rod 20, or any suitable means, can be connected to the lower end of the lever 10 to control the brake thus operated. Said rod 20, when thus connected, exerts a pull on the pivotal point 1?, through the lever 10, using the pivotal point 18 as a fulcrum, which fulcrum slides on the rod 5 in the man- Ubviously, however, the said rod 20, or any suitable means for this purpose, can be connected to pull on the pivot 17 in any suitable or desired manner. The springs 18 and 1d expand (when the pull on the rod 20 is discontinued) to expand the band and thus release the brake.

Now, it will be seen that a pull on the 'rod 20 is translated into a pull or tensile strain on the member 7, as the link 11 pushes downward and outward on the end of the rod, thus exerting a pull on said member. This is advantageous and necessary or desirable in some cases.

The rod5 may have any suitable or desired shape, and the entire brake rigging may have any suitable or desired position.

The rod 5, it will be seen, forms a positive tie directly across the gap between the ends of the band, so that the band is firmly held in contracted condition on the a e a support 16, with some looseness, sov

drum, and whereby the mechanism does not yield and allow the band to slip on the drum. in other words, the torque of the drum does not tend to widen the gap in the band, and the band is thus prevented from intermittently gripping and relaxing its hold on the drum, and does not vibrate or rattle.

Preferably, the lever 10 and the link 11 are double or duplicated at opposite sides of the rod 5 to balance the action, in a manner that will be readily understood.

The element 7, of course, is a sprin support, and in order to contract the brake band 2 a pull must be exerted on this spring support, by the rod 20 through the medium of the elements and 11, and the devices for producing this pull serve thereby to contract the brake band.

It will be seen that the spring support 7 is secured on one end of the band, and that the pull is exerted on its free end, this free end being attached to the lower end of rod 5 in the manner explainet. Thus the rod 5 has engagement with the spring 7 and also with the two end portions 8 and lwhich connect the opposite ends of the band to the operating mechanism, whereby said mechanism has a three-point connection with the band, in effect, one through the portion 3, another through the portion 4-, and a third connection through the spring 7 shown and described. The spring 7, therefore, has nothing to do with preventin rotation of the band, as such rotation is prevented by the elements and 16 previously explained.

What I claim as my invention is:

1. In combination with a motor vehicle wheel, a friction brake therefor comprising a drum which turns with the wheel, a brake band on said drum, and. toggle mechanism for contracting the band on the drum, comprising a support for the hand and a spring secured to said band to form a resilient support for said toggle mechanism, said spring having a pull or ensile strain imposed thereon by the operation of said mechanism.

2. In a friction brake, the combination of a brake band, mechanism for contracting the band, means to operatively connect the ends of the band to said mechanism, a mem ber secured at one end to and supported by the band to provide a fulcrum for said mechanism, said mechanism engaging said member as well as said means on the two said member sustaining a pull or tensile strain when said mechanism is operated to contract the band.

4:. In a friction band brake, the combination of a brake band, a rod having a sliding engagement with one end of the band and a pulling engagement with the other end thereof, a link pivoted on the rod, a lever forming a toggle with said link and pivoted to push on the end of the band which slides on the rod, so that said rod forms a tie across the gap between the ends of the band, a member on the band to support the end of said rod, which member sustains a pull or tensile strain when the toggle is operated by said lever to contract the band, and spring means to expand the band.

5. A structure as specified in claim gt, said member being a spring. i

6. A structure as specified in claim 4, in combination with means to exert a pull on said lever to contract the band and whereby said member sustains a pull or tensile strain when said toggle is operated.

7. A structure as specified in claim 4:, said lever having some endwise movement along the rod when the toggle is straightened to contract the band, and said link imposing a pull. on said member when the lever is moving toward the rod.

8. The improved friction band brake, sub stantially as shown and described, having a spring support mounted at one end and upon which to exert a pull to contract the band,

devices to exert such a pull on the free end of said spring support, which end is movable relatively to the hand, because of the flexibility of said spring, and means operated by said devices to contract the brake band.

CHAUNCEY L. C. MAGEE. 

